Hi,
I let Arena play two games (15s/move) between both versions.

As black, Bataais' hacked version cleaned up material, reaching an overwhelming king + 2 rooks, 1 bishop, 2 knights and 4 pawn against genuine Delta-1's isolated king - but the game ended in a draw (3-fold rep).
As white, the hacked version won by checkmate with a large material advantage (king + 1 queen, 1 rook, 1 bishop, 1 knight, 4 pawns against king + 1 rook, 1 bishop, 1 pawn).

How to play both: surely many ways, this one is quite simple
- in MessChess, I created a hacked_roms new directory containing Bataais' ROM
- in Arena, I duplicated my Delta-1 engine and updated each with command line parameters:

ccdelta1 -rompath roms
ccdelta1 -rompath hacked_roms

You need to specify both, as without -rompath parameter the default is used from ccdelta1.ini file, where the latest used configuration is memorized. So better force it, or you will end using the hacked one anyway.

Of course, on hacked engine start, you need to manually skip the warning about the unexpected ROM.

Have fun,
Eric